What is the feature of barter system

Which of the following studies is linked most directly to the establishment of the national research act in 1974 and ultimately to the belmont report and federal regulations for human subject protection? a. the public health service tuskegee study of untreated syphilis in the negro male.b. stanford prison experiment (zimbardo).c. tearoom trade study (humphreys).d. the harvard t3 study.

Why is this statement not a hypothesis? sunflowers require soil and plenty of sunlight and water to grow and thrive. a. it is a well-known fact. b. it is a proven theory. c. it is not falsifiable. d. it is difficult to test.

What is the difference between the kurds and the shia muslims? a the kurds are a religious group while the shia muslims are an ethnic group. b the kurds and the shia muslims are religious groups. c the kurds are an ethnic group and the shia muslims are a religious group. d the kurds and the shia muslims are ethnic groups.